Liquid electrophotographic ink composition

Abstract

Described herein is a liquid electrophotographic ink composition comprising a first thermoplastic resin comprising a copolymer comprising an alkylene monomer and a monomer comprising an epoxide group, and a second thermoplastic resin comprising a copolymer comprising a monomer comprising an anhydride group.

1 . A liquid electrophotographic ink composition comprising:
 a carrier liquid   one or more pigments;   a first thermoplastic resin comprising a copolymer comprising an alkylene monomer and a monomer comprising an epoxide group, and   a second thermoplastic resin comprising a copolymer comprising a monomer comprising an anhydride group.   
     
     
         2 . The liquid electrophotographic ink composition according to  claim 1 , wherein the monomer comprising an epoxide group is an ethylenically unsaturated monomer comprising an epoxide group. 
     
     
         3 . The liquid electrophotographic ink composition according to  claim 2 , wherein the ethylenically unsaturated monomer comprising an epoxide group is an ester of an ethylenically unsaturated carboxylic acid and an epoxide group-containing alcohol. 
     
     
         4 . The liquid electrophotographic ink composition according to  claim 3 , wherein the epoxide group-containing alcohol comprises a terminal epoxide group. 
     
     
         5 . The liquid electrophotographic ink composition according to  claim 1 , wherein the copolymer of the first thermoplastic resin is poly(ethylene-co-glycidyl methacrylate). 
     
     
         6 . The liquid electrophotographic ink composition according to  claim 1 , wherein the monomer comprising an anhydride group is an ethylenically unsaturated monomer comprising an anhydride. 
     
     
         7 . The liquid electrophotographic ink composition according to  claim 6 , wherein the ethylenically unsaturated monomer comprising an anhydride group is a maleic acid anhydride. 
     
     
         8 . The liquid electrophotographic ink composition according to  claim 1 , wherein the copolymer of the second thermoplastic resin further comprises at least one monomer selected from the group consisting of an alkylene monomer and alkenoic acid alkyl ester monomer. 
     
     
         9 . The liquid electrophotographic ink composition according to  claim 8 , wherein the alkenoic acid alkyl ester monomer is a propenoic-C1 to C4-alkyl-ester monomer. 
     
     
         10 . The liquid electrophotographic ink composition according to  claim 1 , wherein the alkylene monomer is selected from the group consisting of ethylene and propylene. 
     
     
         11 . The liquid electrophotographic ink composition according to  claim 1 , wherein the copolymer of the second thermoplastic resin is poly(ethylene-co-ethylacrylate-co-maleic acid anhydride). 
     
     
         12 . The liquid electrophotographic ink composition according to  claim 1 , wherein the molar ratio of the monomer comprising an anhydride of the copolymer of the second thermoplastic resin to the monomer comprising an epoxide of the copolymer of the first thermoplastic resin is about 0.4 to about 1.7 based on the weight percentage of the respective monomer in the respective copolymer. 
     
     
         13 . A method of printing comprising:
 liquid electrophotographically printing a liquid electrophotographic ink composition on a surface of a substrate, wherein the liquid electrophotographic ink comprises a first thermoplastic resin comprising a polymer of an ethylenically unsaturated monomer comprising an epoxide group, and a second thermoplastic resin comprising a polymer of an ethylenically unsaturated monomer comprising an anhydride group and an alkenoic acid alkyl ester monomer; and   applying the liquid electrophotographic ink composition on the surface of the substrate such that the epoxide group and the anhydride group react with the surface of the substrate and crosslink.   
     
     
         14 . A substrate having liquid electrophotographically printed thereon a liquid electrophotographic ink composition comprising a first thermoplastic resin comprising a copolymer comprising an alkylene monomer and a monomer comprising an epoxide group, and a second thermoplastic resin comprising a copolymer comprising a monomer comprising an anhydride group, wherein the epoxide group and the anhydride group have reacted with the surface of the substrate and have crosslinked. 
     
     
         15 . The substrate according to  claim 14 , wherein the substrate is a multi-layer substrate.